Polyetrafluoroethylene pressing accessory



March 17, 1959 H. JAcoBsoN 2,877,577

POLYTETRAFLUOROETHYLENE PRESSING ACCESSORY Filed 001:. 29, 1954 HARRY JA COBSON,

1N VEN TOR.

A TTORNE Y.

United States Patent POLY'IETRAFLUOROETHYLENE PRESSING ACCESSORY Harry Jacobson, Sherman Oaks, 'Califl, assignor to W. S.

Shamban & Company, "Culver City, Calif., 21 corporation of California Application October 29, 1954, Serial No. 465,577

4 Claims. (Cl. 38-66) This invention relates to a press plate for attaching to the head of garment steaming and pressing machines.

In press plates used for steaming and pressing garments the perforated portion covering the bottom face of the pressing head is usually made of metal, for example, a perforated aluminum sheet, which has many known disadvantages.

In accordance with my invention I have discovered that a surprisingly improved press plate results when this perforated face or pressing surface is made of a sheet of polytetrafluoroethylene resin or plastic, particularly, for example, that polytetrafluoroethylene resin known and sold under the trademark designation Teflon.

A press plate having the face or pressing surface made of a perforated sheet of polytetrafluoroethylene plastic,

in accordance with my invention, surprisingly, not only is capable of withstanding the temperatures involved in connection with the steaming in conjunction with the pressing operation, but also the resulting surface is not corroded as is the case with a metallic surface and hence stays clean and does not leave products of corrosion on the garment being pressed and does not stain the garment. Moreover, it is an exceedingly important aspect of my invention that the press head, having the polytetrafluoroethylene surface, can effectively press a garment having a hard object suchas an ornament or abutton thereon without damaging such ornament or, button, impairing the garment or the pressing surface. Any deformation to the Teflon material is temporary and soon disappears. The pressed clothes look better. and look more like new. Still further, the surface of the fabric of the garment when pressed with the pressing'head in accordance with my invention receives a satisfactory press without producing the well-known undesibale shiny surface to the garment. That is, the polytetrafluoroethylene surface is effective to provide the desired press to the fabric without affecting the threads causing a shiny appearance to a portion of the fabric. The pressing head in accordance with my invention will press uniformly over an uneven surface. No second operation is necessary. The press is complete the first time. Thus, the operator can work faster. Less pressure is required to obtain the same and even better pressing results. Undesirable condensation of steam is avoided. The pressing head in accordance with my invention is easy to maintain, will not clog and can be wiped clean easily. Because of low heat radiation from the pressing head the operator can work more comfortably. The head has a longer life.

It is thus an object of my invention to provide a press plate the pressing surface or face of which is made of polytetrafluoroethylene and having new and unexpected properties and advantages.

My invention will be illustrated and exemplified by a description of a specific embodiment thereof taken in conjunction with the accompanying drawings in which:

Fig. 1 shows a garment pressing machine of the type in which the pressing head of my invention is used.

v Patented Mar. 17, 1959 Fig. 2 shows a plan view of the top of the pressing head.

Fig. 3 shows an elevation of the pressing head in Fig. 2. a

Fig. 4 shows a sectional view of the line 4-4 of Fig. .3 and Fig. 5 shows a section on the line 5-5 of Fig. 3.

Fig. 1 shows a steaming and pressing machine of the type commonly used for pressing garments having a pressing head in accordance with my invention shown generally at 1. As is known in the art, the garment is placed on the lower support 2 and the pressing head 1 is pressed down thereupon with the garment between the steaming" and pressing head 1 and the bottom support 2 while steam is supplied through the hollow portion of the pressing head to pass .out the perforations 3 in the press plate in accordance with my invention, made of a perforated polytetrafluoroethylene sheet as. shown at 4.

The attachment for the pressing head, shown in Figs. 2 and 3, carrying the Teflon sheet in accordance with my invention is fastened to the usual pressing head by means of springs 5 connected to a post 6 on the back of the pressing head. A set of such springs and posts is shown at each end of the pressing head as most clearly seen in Fig. 2.

In general, this attachment with Teflon sheet 4 has the shape of the pressing head. The periphery of the Teflon sheet extends upwardly over an angular metal liner 7, and at 8 extends upwardly on one side of the metal liner 7 and is folded downwardly as shown at 9.

" It will 'be understood that the metal liner 7 extends completely around the periphery of the Teflon sheet adapted to fit on the bottom surface of the press head. Also extending around'the periphery are a series of rivets 10' by means of which the folds 8 and 9 of the Teflon sheet are afiixed to the metal liner 7.

The springs '5 are attached to the periphery of the Teflon sheet as shown particularly in detail in Fig. 5. End 11 of the spring 5 is adapted to fit in an eye 12 7 formed of an overlapping piece of metal 13 through the overlapping part of which rivet 14 extends to fasten this overlapping piece of metal to the folds 8 and 9 with metal liner 7 therebetween.

- Extending back of the Teflon sheet 4 and within the pressing head is an arcuate" perforated metallic member 15 for distributing the steam over the surface of the Teflon sheet. As understood in the art steam is supplied to the pressing head within the hollow space 16.

In accordance with this specific embodiment the poly-', tetrafluoroethylene resin sheet is made of Teflon plastic one-sixteenth inch thick 'perforated with 0.020 inch dian'1 eter holes uniformly distributed with about 350 per square inch.

Teflon is Du Ponts trademark applied to the polymers of tetrafluoroethylene. The resin is made by polymerizing gaseous tetrafluoroethylene to yield a solid, granular polymer. The chemical equation involved in this process may be indicated generally as follows:

3 Table I.-.Typica'l properties of "Teflon" [Data given represent standard commercial grades of material and standard methods of testing errcept where otherwise noted] Property Value Method Spec fic gravity- 2. 1-2. 3 D793- 14'l Tensile strength at 77 F., p. s. 1, 500-2, 500 1 D638-44T Elongation at 77 F., percent... 100-200 D63844T Flexural strength at 77 F., p. s. i 000 'DG50-42T Stifiness at 77 F., p. s. i. (0125111.)- 60, 000 D747-43T Impact strength, Izod, -70, 77, 170 F.,

it.-lb,/m 2. 0,4. 0, 6.0 D256-41T Hardness, D Durometer 55-70 Compressive strength, p. s. i., at 0.1%

deformatiom- 1, 700 D695-42T Deformation under load at 50 C under 1,200 1). s. i., percent in 85 hr 4. 8 D62l-43 Heat-distortion temperature, lo

If 270 D648(B)44'l Specific heat, B. t. u./lb./ F 0.25 Coefficient of linear expansion per F.

(77140 F.) 5. 5X10 D696-42T Thermal conductivity, B. t. u;/hr./it.'-/ 1 F./ln. (0.18 in.) 1.7 Ari. P-32 Dielectric strength, short-time, volt/mil .080 in.) 400500 5 D149-40T Surface arc-resistance, seconds. 700 6 B40542 Volume resistivity, ohm-cm 10 D257-38 Surface resistivity at 100% rel. humidity,

megohms 3. 6X10 D257-38 Dielectric constant at 60, 10 10 10 cycles 2. -2. DIED-401 Power factor at 60, 10, 10 cycles. 0. 0005 Dl50-40T Water-absorption, percent 0.00 1 DMD-42 Static coefficient of friction polished steel 0. 09-0. 12 Vapor pressure, mm. H 10 Outdoor weathering no detectable change in 3 yrs.

1 Tensile strength in oriented film may be as high as 15,000 1:. s. i. 2 Specimens do not break.

3 Method of mixtures.

4 Cenco-Fitch apparatus.

5 1000-2000 volts/mil in thicknesses 5 to 12 mils.

Does not track.

1 Not wet by water unless a surface-active agent is added.

* Inciinedplane method.

Outstanding properties are its toughness over a wide range of temperatures, its excellent electrical properties over a wide range of frequencies, its extreme incrtness to chemicals, and its resistance to heat. Normally,

Teflon has a crystalline structure, but when heated above 620 F. it is changed to an amorphous jelly. In the neighborhood of 750 F., it decomposes slowly to yield the gaseous monomer plus small amounts of other gaseous derivatives of fluorine. At temperatures below the transition point, Teflon is remarkably stable. The tensile strength of molded bars kept at 570 F. forone month will drop only 10-20%. At 480 F., the loss in tensile strength is negligible over very long intervals. The material suffers no detectable loss in weight from being baked at the transition temperature (620 F.) for many hours. The chemical resistance of Teflon" is outstanding, It withstands the attack of practically all chemicals except molten alkali metals. It has been boiled n many so e inc udin a Va i y hal g nated hydrocar ons, isot p s. esters, an a ohols, ithout swelling or any other sign of attack. Teflon" can be boiled in aqua regia, hydrofluoric acid, sulphuric acid or nitric acid with no change in weight or properties. It is equally resistant to the attack of strong alkalies. Chlorine, bromine or iodine do not react with Teflon, but fluorine and chlorine trifluoride will react under special conditions. It can be used over the temperature range of 320 F. to 550 F.

The specific embodiments given above are for the purpose of illustrating my invention, and it will be readily understood that my invention includes other modifications within the scope of the following claims.

I claim:

1. A steam pressing device accessory for use in pressing heat sensitive fabrics, said accessory comprising: a perforated sheet of polymerized tctrafluoroethylenc to cover the bottom surface of the pressing device; means connected to said sheet for engagement with the pressing device to prevent relative transverse movement of said sheet across the bottom surface of the pressing device; and means to attach said sheet to the pressing device.

2. A steam pressing device accessory for use in pressing heat sensitive fabrics, said accessory comprising: a perforated sheet of poiyictrafluoroethylene to cover the bottom surface of the pressing device, said sheet having an upturned flange to fit around the sides of the pressing device to prevent relative transverse movement of said sheet across the bottom surface of the pressing device; and means to attach said sheet to the pressing device.

3. A steam pressing device accessory comprising: a perforated sheet of polymerized tctrafluorocthylene to cover the bottom surface of the pressing device; and means connected to said sheet above the bottom surface thereof to attach said sheet to said pressing device in a substantially fixed position contiguous to the bottom surface of the pressing device.

4. A steam pressing device accessory for use in pressing heat sensitive fabrics, said accessory comprising: a perforated shect of polytetrafluoroethylene to cover the bottom surface of the pressing device, said sheet having an upturned flange to fit around the sides of the pressing device; metallic mcans extending about and secured to said upturned flange; and means connected to said metallic means to fix said sheet in a position contiguous to the pressing surface of the device with said flange and-metallic means contiguous to the sides of the pressing device.

References Cited in the file of this patent UNITED STATES PATENTS 2,032,941 Linscott Mar. 3-, 1936 2,486,740 Freeman Nov. 1, 1949 2,556,008 Spalding June 5, 1951 2,570,110 Glatt Oct. 2, 1951 

3. A STEAM PRESSING DEVICE ACCESSORY COMPRISING: A PERFORATED SHEET OF POLYMERIZED TETRAFLUOROETHYLENE TO COVER THE BOTTOM SURFACE OF THE PRESSING DEVICE; AND MEANS CONNECTED TO SAID SHEET ABOVE THE BOTTOM SURFACE THEREOF TO ATTACH SAID SHEET TO SAID PRESSING DEVICE IN A SUBSTANTIALLY FIXED POSITION CONTIGUOUS TO THE BOTTOM SURFACE OF THE PRESSING DEVICE. 